All Questions
13
questions
0
votes
0
answers
92
views
Contours of a DSM render slowly
I am comparing two digital surface maps (dsms generated from drone photogrammetry) taken at two times. The contour lines render quite quickly for one (in seconds) and quite slowly for the other (1–2 ...
- 83
1
vote
0
answers
395
views
Run gdalwarp to rectify a raster (RPC embedded) with DEM but got error: Too many points failed to transform, unable to compute output bounds
I've been trying to rectify an unprojected raster (with RPC model) with digital surface model (DSM) by using gdalwarp command. Here is the command:
gdalwarp \
-co BIGTIFF=YES \
-co "TILED=YES&...
- 258
0
votes
0
answers
452
views
Vertical transformation of DEM from EPSG:3035 to EPSG:4326
I am trying to convert a DEM file from EPSG:3035 (ETRS89-extended / LAEA Europe) to EPSG:4326 (WGS 84) with gdalwarp. EPSG:3035 uses the European Terrestrial Reference System 1989 ensemble datum where ...
- 329
1
vote
1
answer
114
views
Calculating terrain attributes before or after upscaling DEM
This is more of a theory question. I am working on a project that requires the use of topography data, I have a 1KM resolution global DEM to which I will be using GDAL to calculate general topography ...
- 11
1
vote
0
answers
103
views
Terrain correction in SAR image
I am new to the gdal utility. Using DEM data of the Moon, I am trying to perform terrain correction on SAR images. I have a DEM file and SAR data into tif file format. Both DEM and tif file are in ...
- 83
2
votes
1
answer
213
views
sampling error using gdalwarp on a subsetted VRT?
I am currently trying to prepare an SRTM subset including height conversion from EGM96 to WGS84 using gdalwarp. I encountered some strange shifts in part of the image.
Here is a reproducible example:
...
4
votes
1
answer
2k
views
Efficient downsampling with GDAL?
I have a 350go GeoTIFF file with DEM data for the entire world. (a mix of SRTM, EUDEM, etc. ...)
This TIFF file is tiled with a block size of 256*256.
I would like to downsample this file to a lower ...
- 43
1
vote
0
answers
181
views
gdalwarp with DSM as DEM leaves shifted pixels in their original unshifted location
I'm trying to account for building parallax differences between images collected at different viewing angles. When I use a DSM created from VRICON data as my DEM source, I notice that building roof ...
- 11
6
votes
2
answers
1k
views
Working with DEMs: which should I do first calculate slope or reproject?
I have some 10 m digital elevation model rasters in UTM, and I need to generate 30 m resolution slope rasters in Albers.
Which should I do first: reproject the rasters, or calculate slope?
In case ...
- 1,319
0
votes
1
answer
255
views
How to project a large nonortho satelite image on a much smaller high res DEM?
I am currently attempting to orthorectify an image using GDAL. I have a very detailed DEM that I would like to rectify the image on top of. However, the DEM is smaller than the image itself; this is ...
- 529
1
vote
0
answers
573
views
Resampling using gdalwarp gives me no data
I have an image with the following information.
Driver: GTiff/GeoTIFF
Files:test_DEM.tiff
Size is 91, 73
Coordinate System is:
GEOGCS["WGS 84",
DATUM["WGS_1984",
...
- 61
4
votes
1
answer
2k
views
How to remove strange gdaldem hillshade artifacts?
I've downloaded 9 chunks of 1 arc-second NED in IMG format from the National Map. I'm trying to create a hillshade from them.
I'm using:
GDAL 1.10.0, released 2013/04/24
First, I combine them and ...
- 99
3
votes
2
answers
8k
views
How do I know the vertical/horizontal units of my DEM? I'm creating a slope using gdaldem
I'm using gdaldem to create a slope map.
I can apply a scale. The default is 1.
The notes say:
Ratio of vertical units to horizontal.
If horizontal unit of source DEM is degrees (e.g WGS84 ...
- 9,141